you can istall a game exe file that replaces the exe file in your game folder so you do not need the disk. I do this with all my games so I don't need to keep changing my disks to play them.
these are also call nocd files no dvd exe ect.
all of my disks are in new condition with out any scratch too.
an other thing to consider is to never give out your cd keys. The people you give your cd keys out to might sell them, use them in a way that gets them banned by punkbuster, or use them while you want to game keeping you from being able to play the game you paid for.
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